Native Americans, an oil company, Greenpeace, Ronald Reagan and the Russians working together?

What sounds like a whale of a tale actually happened in 1988, and serves as the inspiration for Drew Barrymore’s new movie, “Big Miracle,” opening Friday.

Amid thawing U.S. and USSR tensions at the end of the Cold War, the world became transfixed by the plight of three California gray whales trapped beneath a thick sheet of ice 5 miles long in northern Alaska.

“The core of it is people putting their agendas aside for one minute and doing something together,” says Barrymore, who plays a Greenpeace worker protecting the whales from the competing interests of an Inuit tribe that wants to harvest them, and Ted Danson’s Northern Alaskan Oil Company that’s more interested in scoring an Arctic drilling contract.

But everyone loves whales, so even the clashing groups eventually find common ground to rescue our flippered friends.

“It’s okay that we all don’t agree on things,” Barrymore says, “but to just say, ‘We are going to work together on this even though I can’t stand what you stand for,’ I think, is just great.”

Especially in an election year.

Barrymore was born for this role. The philanthropist has supported endeavors including Much Love Animal Rescue and the United Nations World Food Programme, as well as spurring youth to vote with her 2004 directorial debut, the documentary “The Best Place to Start.”

She found a kindred spirit in Cindy Lowry, her real-life Greenpeace counterpart. The two became fast friends while the actress was researching her role.

“We actually really clicked, and we found out that we were a lot alike: feisty and really passionate and wrapped up in our work,” says Barrymore.

“She and I would go hiking and talk about life. She gave me her jewelry and clothes, and I actually wear them in the movie. It was really cool and meaningful.”

The cast and crew drew from archival news footage that kept viewers around the globe glued to their sets as the U.S. National Guard and the locals in Point Barrow, Alaska, worked feverishly to free the whales before turning to neighboring Russia for help.

Animatronic puppets were used in place of actual whales, huddling beneath a shrinking breathing hole that’s keeping them alive.

“We would have liked to work with real ones, but you don’t want to harm the whales,” says Barrymore, an animal lover and ASPCA supporter.

“The puppets were amazing, though, and I love that they were not all CGI. That was really helpful to the believability of the film. I feel like you’ll sense that when you watch it. They are not painted in.”

Much of the filming was done in the actual bitter Arctic chill, much to Barrymore’s dismay.

“I’m a real priss about the cold, so I’m not going to claim that I was excited about it,” she laughs.

“If you have the right clothes on and the right gear it’s actually okay,” she says, swearing by her Canada Goose jacket and Sorel boots, “but there is no doubt — it’s as cold as anything I ever experienced.”

“We would play a lot of poker on set,” says Barrymore, who confesses that Bell is a closet card shark, “and we went to dinner.”

She also embraced a lot of quiet time on her own. “I got into hot yoga, and coming home to my dog and chilling out watching an old movie,” she says.

“I wrote a lot of letters back and forth to my friends,” she adds. “It was nice to revive the snail-mail campaign. I love it.”

Barrymore has celebrated some recent big miracles of her own, most notably her engagement to art consultant Will Kopelman — she reportedly is studying to convert to Kopelman’s Jewish faith

.

No wonder she’s drawn to the personal stories that pepper her new film.

“This all really happened. It’s all true,” she marvels, “and it has so much going on: That Tom Brokaw loved the story, and so it went national. And people got involved, and people disagreed, and things were done that were totally unprecedented at the time.

“And people fell in love, and the whales were saved to the best of everyone’s ability, and I just think that is all rather extraordinary.”